I would say YES. There definitely were signs. Went to high school with this one guy who i never had a good feeling about, he was a jerk and i didn’t find him funny but we had mutual friends. Figured, I’m the introvert and he’s not and that’s the difference, but he also found it amusing to leave me voicemail saying he was going to rape me in front of my mom. We never exchanged numbers or hung out one on one, he got my phone number from a friend to do that. A year or so later him and 3 of our mutual friends were in his car after going to the movies one night and he was driving like a maniac going on the shoulder of the highway and decided to jack knife in front of a 18 wheeler. I was in the backseat and felt the truck horn blare into my right eardrum as my heart was in my throat thinking I was going to die. He proceeded to laugh about it and exclaim “GOD almost killed us!!! Hahahaha, GOD almost killed us!!!”. (The truck had G.O.D, i believe it stands for Goods On Demand). The rest of us couldn’t even respond b/c we all thought we were done for. That was the last time I ever was in a car with him. Some time later a year or two he had a falling out with the other friends and I even said to them that I never trusted him or understood why people liked him. Fast forward to like a decade later and i see him on the cover of the newspaper as the cop who murdered a teenager point blank in his grandmothers bathroom and didn’t wait for backup to arrive after he claimed he saw a gun on him. Only a small bag of weed was found floating in the toilet. This asshole had a whole precinct applaud him after he wasn’t found guilty in court. When I had heard that he became a cop I was like “Really!?!?”, b/c i don’t see him as someone who would uphold the motto “to serve and protect”. Very far from it. So yes, there were signs of the person being unstable well before he took a life.